A satellite communication system has a double-layered earth orbit satellite constellation with a lower first orbit altitude and a higher second orbit altitude. In the satellite communication system, first and second communication satellites are deployed in respective earth orbits located at the first and second orbit altitudes to each have first and second satellite communication stations, respectively. Small terminals and large terminals are further provided as earth stations on the earth. Each first satellite communication station communicates with the small terminals and communicates with the first satellite communication stations of adjacent first communication satellites within the same earth orbit and the second satellite communication stations, and each second satellite communication station communicates with the large terminals and communicates with the second satellite communication stations of adjacent communication satellites within the same earth orbit, the second satellite communication stations of the second communication satellites of both adjacent earth orbits, and the first satellite communication stations.